What are the main buzzwords today in the GIS market? Let's place the meaning of these ones too, so beginners can enjoy the topic as well.

Example: SDI

"A spatial data infrastructure (SDI) is a framework of spatial data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way. Another definition is the technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data." wikipedia definition

"The term implies easy, fast integration, frequently using open APIs and data sources to produce enriched results that were not necessarily the original reason for producing the raw source data.
To be able to permanently access the data of other services, mashups are generally client applications or hosted online. Since 2010, two major mashup vendors have added support for hosted deployment based on "Cloud computing" solutions."

"The Geospatial Web or Geoweb is a relatively new term that implies the merging of geographical (location-based) information with the abstract information that currently dominates the Internet. This would create an environment where one could search for things based on location instead of by keyword only – e.g. “What is Here?”."(Wikipedia)

Book by Scharl Tochtermann will give you much more detailed overview of the topic. Also, check ESRI whitepaper on this issue.

...the process of adding geographical identification metadata to various media such as photographs, video, websites, or RSS feeds and is a form of geospatial metadata. These data usually consist of latitude and longitude coordinates, though they can also include altitude, bearing, distance, accuracy data, and place names. It is commonly used for photographs, giving geotagged photographs.

Becoming more and more common, particularly with Facebook Places, Twitter geotagging, and geotagging photos in Flickr. We hear a lot about this in the office as more people are getting on board.

"Neogeography literally means "new geography", and is commonly applied to the usage of geographical techniques and tools used for personal and community activities or for utilization by a non-expert group of users. Application domains of neogeography are typically not formal or analytical." (wikipedia)

Andrew Turner gave a nice introduction to the topic in his book. Try also GIS lounge post for more resources.

Geodesign is a set of techniques and
enabling technologies for planning
built and natural environments in an
integrated process, including project
conceptualization, analysis, design
specification, stakeholder
participation and collaboration,
design creation, simulation, and
evaluation (among other stages).
"Geodesign is a design and planning
method which tightly couples the
creation of design proposals with
impact simulations informed by
geographic contexts."

In the old days before 'buzz' words existed this was called 'Cartography'
–
Mapperz♦Sep 19 '10 at 15:10

1

It has all of the qualities of a great buzzword: redundant with existing terms, little intuitive meaning to anyone outside the field, and attempts to instill a sense of authority.
–
bwreillySep 19 '10 at 23:16

As defined by the participants in the "Mapping for Change International Conference (PGIS'05)" which took place in Nairobi, Kenya in September 2005, Participatory GIS (PGIS) is an emergent practice in its own right; developing out of participatory approaches to planning and spatial information and communication management. The practice is the result of a spontaneous merger of Participatory Learning and Action (PLA) methods with Geographic Information Technologies (GIT). PGIS combines a range of geo-spatial information management tools and methods such as sketch maps, Participatory 3D Models (P3DM), aerial photographs, satellite imagery, Global Positioning Systems (GPS) and Geographic Information Systems (GIS) to represent peoples’ spatial knowledge in the forms of virtual or physical, 2 or 3 dimensional maps used as interactive vehicles for spatial learning, discussion, information exchange, analysis, decision making and advocacy4. Participatory GIS implies making GIT available to disadvantaged groups in society in order to enhance their capacity in generating, managing, analysing and communicating spatial information. (Wikipedia)

"Public Participation Geographic Information Systems (PPGIS) was born, as a term, in 1996 at the meetings of the National Center for Geographic Information and Analysis (NCGIA). PPGIS is meant to bring the academic practices of GIS and mapping to the local level in order to promote knowledge production. The idea behind PPGIS is empowerment and inclusion of marginalized populations, who have little voice in the public arena, through geographic technology education and participation. PPGIS uses and produces digital maps, satellite imagery, sketch maps, and many other spatial and visual tools, to change geographic involvement and awareness on a local level." (Wikipedia)

Geoweb, web mapping, web gis, ppgis, pgis, VGI or some form or another of these terms. There isn't really a great way to differentiate them, but I have my own little interpretation (I need to, grad student in Geography here).

Web GIS: A GIS implemented using the web or internet technologies to connect the multiple parts (storage, presentation, analysis). Notice that web mapping is a subset of web GIS, as it only provides storage and presentation (directions, while a sort of analysis, is not the only analysis needed to make a GIS).

(Public) Participatoy GIS: The long dream of Humanists in Geography, where a participatory process is driving the components of GIS (including storage, presentation and analysis). No one has a clear understanding what this would look like or what it is. If you want to open the participatory process, you can put the extra P in the front (Public).

Volunteer Geographic Information: The clearest part of (P)PGIS thus far: participatory data gathering. This is where you enable the collection of data to be participatory, like the OpenStreetMap project. Of course, the process is not completely PPGIS yet, as the data collection is indeed open, but cleanup, storage, dissemination and maintenance are not as open as one would hope.

The process and methodology of integrating quantitative data(position, quality, etc) about your infrastructure (transmission lines, roads, etc) into a GIS platform in order to manage and observe the lifecycle of these items.

Distributed GIS concerns itself with GI Systems that do not have all
of the system components in the same physical location. This could be
the processing, the database, the rendering or the user interface.
Examples of distributed systems are web-based GIS, Mobile GIS,
Corporate GIS and GRID computing.

and well, Web GIS applicatoins belong here ^^ This is the umbrella term.

A great trend is the use of 311 applications. Take a look at CitySourced
You can take a photo with your iphone, and via an app, send a picture of that graffiti/pothole/shopping trolley, and the council will react to it and fix the issue.

Just because geographic info is volunteered does not necessarily mean it has not been captured by a trained surveyor. When I bought my house I had it surveyed by a licensed surveyor. If I wanted to, I could scan the survey and voluntarily post it onto the web.
–
Kirk KuykendallSep 17 '10 at 13:21

The smart grid is made possible by applying sensing, measurement and control devices with two-way communications to electricity production, transmission, distribution and consumption parts of the power grid that communicate information about grid condition to system users, operators and automated devices, making it possible to dynamically respond to changes in grid condition.

Grid computing allows for the sharing of processing power, enabling the attainment of high performances in computing, management and services. Grid computing, (unlike the conventional supercomputer that does parallel computing by linking multiple processors over a system bus) uses a network of computers to execute a program. The problem of using multiple computers lies in the difficulty of dividing up the tasks among the computers, without having to reference portions of the code being executed on other CPUs.

In computer science and information science, an ontology is a formal representation of knowledge as a set of concepts within a domain, and the relationships between those concepts. It is used to reason about the entities within that domain, and may be used to describe the domain.